How to fill out a PDF on iPhone — in Files, and in Safari
To fill out a PDF on an iPhone, open it in Files, tap the form-filling button, then tap each blank and type. When that button is not offered, open Fill PDF Forms in Safari: it lists every real field as a control and saves a filled copy on the phone.
A form arrives on your phone and the plan to print it, fill it in by hand and photograph it lasts about four seconds. The iPhone fills in PDF forms on its own, and for most forms that is the route to take. The browser tool further down is for the times the built-in one is not offered, and for seeing exactly which fields a file really has.
How do I fill out a PDF form on my iPhone?
Open the PDF in the Files app, tap the form-filling button, tap a blank field and type. Apple documents this for iOS 17 and later, and on iOS 26 and later the Preview app does the same job. In Safari, Fill PDF Forms lists each real field as its own control and saves a filled copy.
The Apple route has two things the browser route does not. It fills fields in place on the page, so you see the form as its author drew it, and from iOS 17.2 it offers AutoFill from your contact card for your personal details. It also has an Add Text Form Box option for typing where the form has no field at all.
Fill out a PDF in Safari, step by step
Open the tool in Safari
Go to Fill PDF Forms. No App Store download, no account.
Choose the form from Files
Tap the drop area and pick the PDF. The file is scanned at once and a count appears, such as "7 fields detected".
Work down the list
Each field is a card showing its name from the file and a tag for its type. Text fields open the keyboard, checkboxes and radio buttons are tap targets, and dropdowns and list boxes become menus. Anything already filled in arrives with its current value.
Save the filled copy
Tap Save filled PDF. The answers are written into the real form fields and the copy downloads under the original file name with _filled added. The original file is read and never changed.
The list is the point on a phone. There is no pinching in to hit a box a few millimetres tall, because the boxes are full-width controls in a single column. The cost is that you do not see the page while you type, and the names come from whoever built the form, so a field can be called full_name or it can be called Text12. One small annoyance to expect: the text boxes are set in 14-pixel type, and Safari on iPhone zooms in on a tapped text box smaller than 16 pixels.
How do I fill out a PDF form that was emailed to me?
Save the attachment to Files first. Open the email, tap the PDF, tap Share, then Save to Files. From there, open it in Files to fill it in with the built-in tools, or choose it from the drop area in Fill PDF Forms.
Can I fill in a PDF form on my phone?
Yes, on an iPhone or an Android phone. Fill PDF Forms is the same web page in Safari and in Chrome, and the work happens in the browser tab: the form is read, filled and saved on the phone, and the file is not uploaded. There is no server for it to go to.
What the iPhone keyboard types that a form cannot draw
Most of what a phone keyboard produces lands correctly. Emoji and non-Latin scripts do not. To find the line, we built a test form, filled it through the real save path, and read the result back with a different PDF library from the one that wrote it.
- The curly apostrophe, curly quotes, long dash and ellipsis that the iPhone keyboard substitutes as you type all drew correctly.
- Accented Western European letters such as é and ü drew correctly.
- A thumbs-up emoji drew as a question mark. A name typed in Cyrillic drew as four question marks. The Polish letters in the city name Łódź drew as question marks while the ó between them survived.
The detail that makes this worth knowing: in every one of those cases the field still stored exactly what was typed. A form field holds two things, a value and a drawn picture of that value, and only the picture went wrong. A viewer that redraws fields from their values shows your text; one that shows the saved picture shows question marks. No error appears either way, so if you typed anything beyond Western European letters, open the saved copy and look before you send it. Why PDF text turns into question marks explains the font limit behind it.
Why can I not fill in a fillable PDF form?
Usually because it is not fillable. A scan of a paper form, or a form that was drawn and exported, has printed boxes and no fields, and the tool answers "No fillable form fields found". The other cause is a password: a form that needs one to open is turned away, and the no-fields notice shows beneath the password message although the fields exist. Unlock it first.
Three quieter cases raise no error:
- A text field with a character limit rejects a longer answer whole. A five-character postcode field holding 90210 was given 90210-1234, and the saved file still said 90210. The text box on screen does not enforce the limit, so nothing stops you typing past it.
- A field the author marked read-only still gets an editable box here, and what you type into it is saved.
- A dropdown, radio group or list box that arrives with a choice already made cannot be set back to blank. The desktop guide covers that one in full.
How do I turn my PDF into a fillable form?
Not with this tool: it fills fields that already exist and does not create them. Apple does not describe its own form filler as a form builder either. On the phone, the practical answer is to type onto the page instead: Add Text Form Box in Files, or the text tool in Annotate PDF, places words wherever the printed lines are.
What the saved file is
Still a form. The answers are stored as field values and nothing is added to the text of the page, so the person you send it to can tap into a box and change what you wrote. The file is edited in place and not rebuilt, so its title came through in every test save. When the answers need to be final, run the filled copy through Flatten PDF in its form-fields mode, and do that before merging or splitting it, because those rebuild the document and leave the form behind.
If the form also wants a signature, fill it first and sign second: signing a PDF on an iPhone covers both the Markup route and the Safari one.
